diff --git a/packages/core/src/kit/theme-header.tsx b/packages/core/src/kit/theme-header.tsx
index 1b5eb81..6026604 100644
--- a/packages/core/src/kit/theme-header.tsx
+++ b/packages/core/src/kit/theme-header.tsx
@@ -105,7 +105,10 @@ export function ThemeHeader({
               </div>
             </form>
           )}
-          <LanguageSwitcher />
+          {/* 语言切换器：小屏隐藏（避免 375-420px 视口撑破 header） */}
+          <div className="hidden sm:block">
+            <LanguageSwitcher />
+          </div>
           <ModeToggle />
           <UserMenu />
 
diff --git a/packages/core/src/pages/[locale]/(marketing)/tools/[slug]/page.tsx b/packages/core/src/pages/[locale]/(marketing)/tools/[slug]/page.tsx
index 8b638a2..62b2e89 100644
--- a/packages/core/src/pages/[locale]/(marketing)/tools/[slug]/page.tsx
+++ b/packages/core/src/pages/[locale]/(marketing)/tools/[slug]/page.tsx
@@ -130,11 +130,20 @@ export async function generateMetadata({ params }: ToolDetailPageProps) {
   const description =
     locale === "zh" && tool.descriptionZh ? tool.descriptionZh : tool.descriptionEn;
 
+  // meta description：tagline + 描述组合并截断到 ~155ch（SEO 最佳实践）
+  const metaDescBase =
+    [tool.taglineEn, description, tool.descriptionEn]
+      .filter(Boolean)
+      .join(". ")
+      .replace(/\.\s*\./g, ".") || `${t("subtitle")} - ${name}`;
+  const metaDescription =
+    metaDescBase.length > 155 ? `${metaDescBase.slice(0, 152)}...` : metaDescBase;
+
   return generatePageMetadata({
     locale,
     path: `/tools/${slug}`,
     title: `${name} - ${t("title")}`,
-    description: tool.taglineEn || description || `${t("subtitle")} - ${name}`,
+    description: metaDescription,
     ogImage: tool.coverImageUrl || tool.logoUrl || undefined,
   });
 }